We have developed superconducting actuators made of YBCO superconductors, and analyzed dynamic characteristics of the actuators.(1) We fabricated a rotating actuator of which driving force is Meissner repulsion between the stator composed of a YBCO sintered pellet and YBCO fibers prepared by our original "Alginate method", and the Nd permanent magnet rotor of 1 mm in diameter. Although this actuator did not rotate continuously, the principle of superconducting actuators was confirmed by this actuator.(2) We next tried to drive the rotating actuator with an electro-magnetic force between the permanet magnet rotor and a rotating magnetic field. A smooth continuous rotation was achieved with the maximum rotation of 1710 rpm. Fluctuation of the rotor pivot was as small as 10 mum or less.(3) A superconducting reciprocating actuator has been developed. A permanent magnet floated on a YBCO stator was driven by a vibrating magnetic field. Reciprocation strokes of mum to mm were obtained. Smooth continuous reciprocation was achieved with the maximum reciprocation frequency of more than 3000 cycle per minute. We analyzed the motion of the reciprocating actuator with a mechanical model composed of a spring and a dashpot. The result of the analysis agreed with the experiment.